The A7 has been closed between Peffermill Road and Old Dalkeith Road.
A picture taken by a witness showed a large emergency response at the scene, with Police Scotland, the Scottish Ambulance Service and the Scottish Fire and Rescue Service all in attendance.
A Scottish Fire and Rescue Service spokesperson said: “We were alerted at 7.35am on Tuesday, November 16 to reports of a collision involving one lorry near to a railway bridge at Cameron Toll roundabout, Edinburgh.“Operations Control mobilised three appliances and specialist resources to the scene.“One casualty was in the care of the Scottish Ambulance Service and crews made the area safe before leaving the scene.”
Police Scotland and the Scottish Ambulance Service have been contacted for comment.
Twitter account Edinburgh Travel News has advised drivers to “avoid the whole area if you can”.
Several Lothian buses have been diverted.